Carbonyl bisulfite adducts as fixers for halogen liberating free radical systems

ABSTRACT

Photographic material is provided which comprises a lightsensitive photoactivator capable of producing a free radical upon exposure to light, a color modifier which provides a visible color change by the action of a free radical, and a fixing agent which includes a bisulfite adduct. Activation of the fixing agent results in release of the bisulfite compound to inactivate the photoactivator and prevent photolytic color change.

United States Patent Itano et al.

CARBONYL BISULFITE ADDUCTS AS FIXERS FOR HALOGEN LIBERATING FREE RADICAL SYSTEMS Inventors:

Assignee:

Filed:

Appl. No.:

Kohei Itano, Hachioji; Shoichiro Hoshino, Tokyo; Akira Kato, Hachioji, all of Japan Keuffel & Esser Company, Morristown, NJ

Mar. 16, 1967 Foreign Application Priority Data Mar. 18,1966 Japan 41-16712 US. Cl 96/148 R; 96/89; 96/90 R Int. Cl. G03c 1/72; G030 1/52; G030 5/24 Field of Search 96/89, 90, 48 R References Cited UNITED STATES PATENTS Kendall et al 96/109 X Primary Examiner-Won H. Louie, Jr. Attorney, Agent, or FirmLionel N. White, Esq.

[5 7] ABSTRACT Photographic material is provided which comprises a light-sensitive photoactivator capable of producing a free radical upon exposure to light, a color modifier which provides a visible color change by the action of a free radical, and a fixing agent which includes a bisulfite adduct. Activation of the fixing agent results in release of the bisulfite compound to inactivate the photoactivator and prevent photolytic color change.

8 Claims, 3 Drawing Figures LIGHT-SENSITIVE COMPOSITION "FIXING COMPOSITION SUPPORT z usur-ssusmve COMPOSITION s- -Flxme COMPOSITION I SUPPORT F'lG.

l- JSUPPORT CARBONYL BISULFITE ADDUCTS AS-FIXERS FOR HALOGEN LIBERATING FREE RADICAL SYSTEMS BACKGROUND oETHE, INVENTION Photographic material is known which comprises a light-sensitive free radical generator and a modifier which produces a color change by the action of afree radical. Material of this nature'is describedfor example, in US. Pat. Nos. 3,042,5l*'to 3",O42,5-l9. -S,uch conventional light-sensitive photographic material: is

composed mainly of a photoactivatorcapable of forming a free radical by action of light and'a color modifier showing a visible'color change by action of said free radical. in fixing such conventional photographic material after forming an image by application of imagewise exposure thereto, there has been adopted the so-called heat fixing or solvent fixing methods; Q

According to the heat fixing method, the imagebearing light-sensitive photographic material is heated at a temperature of about l-00200 C todecompose or sublime the residualphotoactivator which hasnot taken part in the formation of image, .so that the .material is no longer changed in color'even .when it is reexposed. According to the solution fixing method the residual photoactivator which has not taken part in the image formation, is dissolved-from the color forming composition, thus fixing the. material against subsequent light exposure. 4 a

However, when fixed in the above manner, the conventional light sensitive: photographic: material suffers from various drawbacks and is not preferable for practical use. For example, when theconventional photographic material is subject to heat fixing treatment, a halogenated hydrocarbon used as photoactivator is decomposed or Sublimated to generate a poisonous gas, which gives detrimental effects to the human body. Particularly, carbon 'tetrabromide andaroyl trihalogenated hydrocarbon, which have been recommended as being effective, are poisonous} as is'well known. It is "As mentioned above, the conventional light-sensitive photographic materials have been greatly inconvenient in fixing treatment and have been low in practical utily -,SUMMARY OF THE INVENTION In accordance with the present invention, there is provided a light-sensitive photographic material free from the above-mentioned drawbacks. That is, the present invention is a light-sensitive photographic material containing a light-sensitive composition composed mainly ofa photoactivator capable of forming a free radical by action of light and a 'color modifier showing a visible color changeby action of said free radical, and a fixing agent comprising a' bisulfite adduct, for example, an addition product of a bisulfite and a compound containing a carbonyl group. The light-sensitive composition and the fixing agent may be formed into separate layers or maybe mixed together in a simple layer coated on a suitable support.

The thus obtained light-sensitive photographic material is exposed to light through an original image or transparency whereby the color modifier is varied in color due to a free radical formed from the photoactivator, and an image is formed'This image is stable, but cannot be stored in a bright place unless theunexposed portion is freed from light sensitivity. Therefore, the photographic material should necessarily be subjected to fiXingLThe light-sensitive photographic material of said that for the human body, the permissible amount of carbon tribromide gas is about 1 ppm. or less in 8 hours, and special precautions are required so as not to inhale the gas. On the other hand, the aroyl trihalogenated hydrocarbon is lower in volatility than carbon tetrabromide, but has a high tear-inducing property, and therefore special precautions are required as in the case of carbon tetrabromid'e. In preparing a lightsensitive photographic material, it is desirable to use; in

order to make the heat'fixin'g thereof more effective, a,

lowered in image resolution to give a copy low'in pra'ctical value. For this, it is necessary to select solvents ca:

pable of dissolving only the composition which has not taken part in image formation.'Such solvents, however,

the present invention contains the fixing agentas mentioned above, and hence does not suffer from such drawbacks as seen in the conventional light-sensitive photographic material. For example, the photographic material of the present invention contains a fixing agent comprising an addition product of a' bisulfite and a compound containing a carbonyl group. This fixing agent is markedly stable and is not decomposed at all during storage and exposure. However, when the fixing agent is treated, for example, with ammonia gas for several seconds to several :minutes, or with a 5-15% aqueous alkali solution for several seconds to several minutes, or is thermally treated at about lOO-250C for several" seconds, it'is readily dissociated to liberate the bisulfite. This liberated bisulfite causes a chemical reaction with the photoactivator to make the latter inactive. Therefore, in the 'fixing of the present photographic material, it is sufficient to subject said material to any of theabove-mentioned treatments so that a bisulfite is liberated from the fixing agent employed. F urther, in fixing the present photographic material by heating, the liberated bisulfite immediately captures the photoactivator, and therefore no poisonous gas is generated to give harm to the human body, unlike in the case of the conventional heat fixing.

As a means to be employed in fixing the present photographic material in the above manner, there may be used, as such, a heat fixing means for heat developable diazo-type copying sheets, a fixing means convention ally used in electrophotography, a drying means for printing papers, a heating means employed in heatsensitive copying apparatus or an ammonia gasgenerating means employed in dry diazotype copying machine.

DRAWINGS FIGS. 1-3 of the drawing show cross-sectional representations of various embodiments of the present invention.

In FIG. 1 the light-sensitive composition 2 is coated over the fixing agent composition 3 on the support 1.

In FIG. 2 the fixing agent composition 3 is coated over the light-sensitive composition 2 on the support 1.

In FIG. 3 the light-sensitive and fixing agent composi tions are combined in a single coating 4 on the support PREFERRED EMBODIMENTS As mentioned above, the light-sensitive photographic materials of the present invention can be fixed simply and at low costs, without giving any harm to the human body and giving any detrimental effects to the photographic characteristics, such as resolution, of the resulting images. Moreover, the present photographic materials are stable even when stored for a long period of time.

Typical examples of the fixing agents to be used in the presentinvention are as shown below, but the invention is not limited'thereto.

. Glutaraldehyde-sodium or potassium bisulfite.

. Propionaldehyde-sodium or potassium bisulfite. lsobutylaldehyde-sodium or potassium bisulfite. Acetylacetone-sodium or potassium bisulfite. Acetonylacetone-sodium or potassium bisulfite. Butyraldehyde-sodium or potassium bisulfite.

. Crotonaldehyde-sodium or potassium bisulfite. Cinnamylaldehyde-sodium or potassium bisulfite. Benzaldehyde-sodium or potassium bisulfite. l0. Acetaldehyde sodium or potassium bisulfite.

l l. Formaldehyde-sodium or potassium bisulfite. l2. Acetone-sodium or potassium bisulfite.

13. Aldol-sodium or potassium bisulfite.

The above-mentioned fixing agents employed in the present invention are maintained in stable state, because the bisulfites have formed addition products with the compounds containing carbonyl groups. It is, therefore, not objectionable as mentioned before that these addition products are incorporated in light-sensitive compositions or layers thereof are formed on the layers of light sensitive compositions. However, when heated or treated with ammonia gas or aqueous alkali solutions, the abovementioned addition products liberate the bisulfites, which exhibit fixing actions by reacting with the photoactivators in the light-sensitive compositions thereby inactivating the photoactivators.

The main components of the light-sensitive compositions are photoactivators and color modifiers.

Typical as the photoactivators are as follows:

I. Compounds represented by the general formula R C X wherein R is an aryl, alkyl, aralkyl, aroyl or alkenyl group or a halogen or hydrogen atom; and X is a halogen atom. These include:

Carbon tetrabromide, Carbon tetrachloride, Hexachloroethane, Pentabromoethane, p-Nitrobenzotribromide,

Bro'motrichloromethane,

Hexabromoethane,

Benzotrichloride,

lodoform,

Tetrachlorotetrahydronaphthalene,

Chloral,

Bromal,

l l l -Tribromo-2-methyl2-propanol,

1 ,1 ,2,2-Tetrabromoe thane,

2,2,2-Tribromoethanol,

Trichloroacetamide,

l,l,l-Trichlorodimethyl-2-propanol, and a,a,a -Trichlorotoluene.

II. Compounds represented by the general formula Rx 0 Br wherein R is an alkyl, aryl or substituted aryl; and X is a halogen atom. These include:

2,4-Dinitrobenzenesulphenyl chloride,

Nitrobenzenesulphenyl chloride.

lV. Compounds represented by the general formula and owherein A is a heterocyclic compound residue which may have a substituent; and R R and R are groups selected from the class consisting of H, Cl and Br, excepting the case where the groups are all H. These include:

w,w,w-Tribromoquinaldine,

w, m-Dibromoquinaldine, 2-w,w,m-Tribromomethyl-4-methylquinaldine, w,w-Dichloromethylquinoline,

'w-Bromolepidine,

2-w-Bromomethylisoquinoline 4-w,m,w-Tribromomethylpyrimidine 4 Phenyl-6-w,w,w-tribromopyrimidine, 2-m,w,w-Trichloromethyl-6-nitrobenzothiazole, 1-Phenyl-3 co,w,w-trichloromethyl-5-w,w,w-tribromolepidine-bromomethylate, a-w,cu-Dibromomethyl-4-chloropyridine, l-Methyl 2-(chloromethyl)-benzimidazole, and 2, 5-Ditribromomethyl-3 ,4-dibromothiophene.

' V. Compounds represented by the general formula wherein X X and X;, are group selected from H, C]

and Br, excepting the case where the groups are all H;

and R is a substituted or non-substituted aryl or hetero residue. These include:

Hexabromodimethyl sulfoxide,

Pentabromodimethyl sulfoxide,

Hexabromodimethyl sulfone,

Trichloromethyl-phenyl sulfone,

Tribromomethyl-phenyl sulfone,

Trichloromethyl-p-chlorophenyl sulfone,

Tribromomethyl-p-nitrophenyl sulfone,

2-Trichloromethyl-benzothiazole sulfone-(Z),

4,6-Dimethylpyridine-2-tribromomethyl sulfone,

Tetrabromodimethyl sulfone,

2,4-Dichlorophenyl-trichloromethyl sulfone,

2-Methyl-4-chl0rophenyl-trichloromethyl sulfone,

2,5 -Dimethyl-4-chlorophenyl-trichloromethyl sulfone,

and

2,4-Dichlorophenyl-tribromomethyl sulfone.

The photoactivators as mentioned above produce free radical by action of light. As color modifiers changing in color by action of free radicals, there are those used as the so-called negative-positive type which are originally colorless but develop color by action of the free radicals, and those used as the so-called positive-positive type which are originally colored but are discolored to another color or are decolored by action of free radicals.

Examples of the former color modifiers are diphenylamine, dibenzylamine, triphenylamine, N-hydroxyethyl-N-ethylaniline, p, p-methylenebis (N, N- diethylaniline) or the like amine compound, and leucocrystal violet, leuco-malachite green, Michlers hydrol, leuco-methylene blue or the like leuco bases of dyes.

Effective as the latter color modifiers are coloring matters of diphenylmethane, triphenylmethane, thiazine, oxazine, xanthene, anthraquinone, iminonaphthoquinone and azomethine types. Examples of these are auramine, Victoria Blue, Benzoylmethylene Blue, Cinnamoylmethylene Blue, Rhodamine, 4-pdiethylaminophenylimino-naphthoquinone, pmethoxybenzoyl-p-diethylamino-omethylphenyliminoacetanilide, and I-phenyl-B-methyl 4-p-diethylaminophenylimino-S-pyrazolone.

The light-sensitive photographic materials of the present invention are composed mainly of such photoactivators, color modifiers and fixing agents as mentioned above. It is, however, needless to say that other auxiliary components may be added thereto.

In the present photographic material the photoactivator yields a free radical by action of light, particularly ultraviolet light, and the color modifier provides a visible color change by action of said free radical, as mentioned before, and in order to enhance the sensitivity of the material, there may be added suitable sensitizers. As the sensitizers usable for the above purpose, there are two kinds; the so-called color sensitizers which broaden the light-sensitive wave length area of photographic material to a visible light zone, and true sensitizers which enhance the sensitivity of photographic material. Effective as the former scnsitizers are sensitizing coloring matters employed in the conventional photography, such as acridine, cyanine, mellocyanine and styryl type dyes: Usable as the latter sensitizers are benzaldehyde, dimethylaminobenzaldehyde, salicylaldehyde, phenylacetaldehyde, ascorbic acid and benzaldehydesulfonic acid. In order to improve the color tones of formed images, the conventional color tone improvers may be added. Further, in order to prevent the discoloration of the backgrounds of formed images, reducing materials such as hydroquinone and metol may be added as discoloration-preventing agents. In addition, the photographic material may be incorporated with a compound capable of yielding alkali on heating, such as urea, so that the fixing action can'be promoted when the material is subjected to heat fixing.

As the support, any of paper, plastic films, glass sheets and metal plates may be used. Generally, however, the use of photographic original sheets and plastic coated papers results in good resolution, high density and clear images.

In forming a layer of the aforesaid light-sensitive composition on the support, the composition may be applied thereto in the form of a solution together with a suitable film-forming high molecular weight binder such as, for example, gelatine; a cellulose derivative, e.g. cellulose acetate or ethyl cellulose; a vinyl polymer, e.g. vinyl chloride or vinyl acetate; or a synthetic rubber, e.g. cyclized rubber or acrylic rubber.

The light-sensitive composition employed in the pres ent invention is usually water-insoluble,while the fixing agent'is organic solvent-insoluble. Therefore, in case the two are to be formed into separate layers, as shown in FIGS. 1 and 2, they may be applied in the form of separate solutions. However, in case the two are to be formed into one layer as shown in FIG. 3, they may be applied in the form of a dispersion of the lightsensitive composition in an aqueous solution of the fixing agent or a dispersion of the fixing agent in an organic solvent solution of the light sensitive composition.

In applying the light-sensitive composition in the form of a solution, as mentioned above, an extender such as saponin may, of course, be used.

Further, in case the light-sensitive photographic material of the present invention is to be brought into the structure as shown in FIG. 1, the fixing agent may be used as such in the form of a powder.

A preferred quantitative ratio of the present components, when used in admixture, is as follows:

Fixing agent 1 10 parts Photoactivator 1 part Color modifier 0.5 3 parts bodiments of the invention.

Example 1 .Diphenylamine l g. Trihromomcthylphenyl sulfone l g. Gclatinc g Water c The following examples illustrate a few preferred em- The above materials were admixed in a-ball mill to form a dispersion. To the dispersion, 4 g. of an acetaldehyde-sodium bisulfite addition product was added, and the mixture was applied, under a red safety light, onto a baryta paper to a dry thickness of 1'2 p. to obtain a light-sensitive photographic material.

The thus obtained dried photographic material was covered with a photographic negativearid was exposed for seconds to an 800 W mercury lamp at a distance of 5 cm., whereby a blue image was immediately obtained. This image-bearing photographic material was heated for seconds on a hot roll having a surface temperature of 180C. to obtain a copy bearing a stable clear image which was not discolored even when allowed to stand in a bright place.

Example 2 Diphenylamine 5 g. Tribromomethylphenyl sulfonc 5 g. Solution A Acetone 100 cc Acetuldehyde-potassium bISUIfiIC 4 g. solution B Water 40 cc 7 The above Solutions A and B were separately prepared. Solution A was first applied onto a baryta paper to a thickness of 1.5cc/m and then Solution B was applied onto the layer of Solution A to a thickness of 3cc./m ,,to obtain a light-sensitive photographic material.

The thus obtained dried photographic material was exposed to light in the same manner as in Example. 1, whereby a blue image was immediately obtained. The image-bearing photographic material was heated for 10 seconds on a hot plate having a surface temperature of 150C. to obtain a copy which was not discolored even when re-exposed.

Example 3 Solutions A and B employed in Example 2 were applied onto a baryta paper in reverse order, i.e. Solution B was first applied onto the baryta paper and then Solution A was applied onto the layer of Solution B. The resulting light-sensitive photographic material was treated in the same manner as in Example 2 to obtain exactly the same results as in Example 2. Example 4 Glutaraldchydcsodium bisulfite 5 g. Cellulose acetate 0.4 g. Acetone cc The above materials were admixed in a ball mill to form a dispersion. To the dispersion, 1 g. of diphenylamine and 1 g. of tribromomethylphenyl sulfone were added, and the mixture was applied onto a baryta paper. The resulting dried light-sensitive photographic material was exposed to light in the same manner as in Example 1, whereby a blue image was immediately obtained.

Subsequently, the image-bearing photographic material was heated at 170C. for 10 seconds to obtain a copy having a clear image which was not discolored even when re-exposed.

Example 5 Ben/.ylamine 4 g. Carbon tetrabromide 6 g. Solution A Acetone cc Glutaraldehydc-sodium bisulfite 4 g. Solution B Water 100 cc The above Solutions A and B were separately prepared. Solution B was applied onto a baryta paper to a thickness of 3 cc/m and then Solution A was applied onto the layer of Solution B to a thickness of 1.5 cc/m The resulting dried photographic material was exposed to light in the same manner as in Example 1, whereby a yellowish brown image was obtained. This image-bearing photographic material was heated for 10 seconds on a hot roll having a surface temperature of C. to obtain a copy which was not discolored at all even when allowed to stand in a bright place.

Example 6 Leuco-malachite green 4 g. Carbon tetrabromide 6 g. Solution A Acetone 100 cc Formaldehyde-sodium bisulfite 10 g. water 100 CC Solution B The above Solutions A and B were separately prepared. Solution A was applied onto a baryta paper to a thickness of 1.5 ce/m and then Solution B was applied onto the layer of Solution A to a thickness of 3 cc/m The resulting dried light-sensitive photographic material was exposed to light in the same manner as in Example 1, whereby a' green image was immediately obtained.

The image-bearing photographic material was allowed to stand for 5 minutes in ammonia gas and was then taken outto obtain a copy which was not discolored even when re-exposed.

Example 7 Leuco-crystal violet 5 g. m1,w-Tribrornoquinaldine 5 g. Solution A Acetone 100 cc Formaldehyde-sodium bisulfite 5 g. Urea 1O g. Solution B Water 100 cc The above Solutions A and B were separately prepared. Solution A was first applied onto a baryta paper to a thickness of 1.5 ec/m and then Solution B was applied onto the layer of Solution A to a thickness of 3 cc/m The resulting dried light-sensitive photographic material was exposed to light in the same manner as in Example 1, whereby a purple image was immediately obtained. The image-bearing photographicrnaterial was heated at 200C. for 5 seconds to obtain a copy which was not discolored at all -even'when re-exposed.

Example 8 g A light-sensitive photographic material obtained in the-same manner as in Example 1, except that 2 g. of hydroquinone was further incorporated, was subjected to the same treatments as in Example 1 to obtain an excellent copy entirely fixed against discoloration of the background.

Example 9 Leuco-crystal violet g. w,w.w-Tribromoquinaldine 5 g. Solution A Acetone 100 cc Formaldehyde-sodium bisulfite g. Water 100 cc soh'mon B The above Solutions A and B were separately prepared. Solution A was first applied onto a baryta paper to a thickness of 1.5 cc/m and then Solution B was applied onto the layer of Solution A to a thickness of 3 cc/m The resulting dried light-sensitive photographic material was exposed to light in the same manner as in Example 1, whereby a purple image was obtained. This image-bearing photographic material was dipped for one minute in a 10% aqueous caustic soda solution to obtain a copy which was not discolored at all even when re-exposed.

Example 10 Leucomalachite green 5 g. Carbon tctrabromidc 5 g. Solution A Acetone 100 cc Formalin-potassium bisulfite 10 g. Water 100 cc B The above Solutions A and B were separately prepared. Solution A was first applied onto a baryta paper to a thickness of 1.5 cc/m and then Solution B was applied onto the layer of Solution A to a thickness of 3 cc/m The resulting dried light-sensitive photographic material was exposed to light in the same manner as in Example 1, whereby a purple image was immediately obtained. The image-bearing photographic material was dipped for 3 minutes in a 10% aqueous ammonia solution to obtain a copy which was not discolored at all even when re-exposed.

Example 1 l Ethylaminophenylimino-naphthoquinone 2.5 g. Tribromomethylphenyl sulfonc 5 g. Solution A Acetone 100 cc FormaIin-sodium bisulfitc 10 g. Water 100 cc solution B The above Solutions A and B were separately prepared. Solution A was first applied onto a baryta paper to a thickness of 1.5 cc/m and then Solution B was applied onto the layer of Solution A to a thickness of 3 cc/m The resulting dried light-sensitive photographic material was of the positive-positive type and was colored to bluish green. This photographic material was exposed to light in the same manner as in Example 1, whereby a clear bluish green image was obtained. The image-bearing photographic material was dipped for 3 minutes in a 10% aqueous ammonia solution to obtain a copy which was not discolored at all even when reexposed.

The above examples have been presented for the purpose of illustration and should not be taken to limit the scope of the present inven tion. It will be apparent that the described examples are capable of many variations and modifications which are likewise to be included within the scope of the present invention as set forth in the appended claims.

What is claimed is:

1. Light-sensitive photographic material comprising a. a support;

b. a photographic composition comprising:

1. a light-sensitive halogen-containing organic photoactivator capable of producing a halogen free radical upon exposure to light, and

2. a color modifier which provides a visible color change by the action of a halogen free radical; and

c. a fixing agent comprising a bisulfite adduct of a compound selected from the group consisting of aldehydes and ketones.

2. Material according to claim 1 wherein:

a. said photographic composition is coated in a layer on said support; and

b. said fixing agent is coated in a layer on said photographic composition layer.

3. Material according to claim 1 wherein:

a. said fixing agent is coated in a layer on said support;

and

b. said photographic composition is coated in a layer on said fixing agent layer.

4. Material according to claim 1 wherein said photographic composition and said fixing agent are intimately dispersed throughout a layer coated on said support.

5. The method of making a permanent image comprising:

a. providing material according to claim 1;

b. imagewise exposing said material to a light pattern for a time sufficient to form a visible color change; and

c. treating said exposed material with heat or alkali in an amount sufficient to dissociate said adduct and liberate said bisulfite to inactivate said photoactivators.

6. The method according to claim 5 wherein said treating step comprises heating said material at about 250C for a time sufficient to dissociate said adduct.

7. The method according to claim 5 wherein said treating step comprises contacting sai material with about a 5-1 5% aqueous alkali solution for a time sufficient to dissociate said adduct.

8. The method according to claim 5 wherein said treating step comprises contacting said material with gaseous ammonia for a time sufficient to dissociate said 

1. A LIGHT-SENSITIVE HALOGEN-CONTAINING ORGANIC PHOTOACTIVATOR CAPABLE OF PRODUCING A HALOGEN FREE RADICAL UPON EXPOSURE TO LIGHT, AND
 1. LIGHT-SENSITIVE PHOTOGRAPHIC MATERIAL COMPRISING A. A SUPPORT: B. A PHOTOGRAPHIC COMPOSITION COMPRISING:
 2. Material according to claim 1 wherein: a. said photographic composition is coated in a layer on said support; and b. said fixing agent is coated in a layer on said photographic composition layer.
 2. a color modifier which provides a visible color change by the action of a halogen free radical; and c. a fixing agent comprising a bisulfite adduct of a compound selected from the group consisting of aldehydes and ketones.
 2. A COLOR MODIFIFIER WHICH PROVIDES A VISIBLE COLOR CHANGE BY THE ACTION OF A HALOGEN FREE RADICAL: AND C. A FIXING AGENT COMPRISING A BISULFITE ADDUCT OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF ALDEHYDES AND KETONES.
 3. Material according to claim 1 wherein: a. said fixing agent is coated in a layer on said support; and b. said photographic composition is coated in a layer on said fixing agent layer.
 4. Material according to claim 1 wherein said photographic composition and said fixing agent are intimately dispersed throughout a layer coated on said support.
 5. The method of making a permanent image comprising: a. providing material according to claim 1; b. imagewise exposing said material to a light pattern for a time sufficient to form a visible color change; and c. treating said exposed material with heat or alkali in an amount sufficient to dissociate said adduct and liberate said bisulfite to inactivate said photoactivators.
 6. The method according to claim 5 wherein said treating step comprises heating said material at about 100*-250*C for a time sufficient to dissociate said adduct.
 7. The method according to claim 5 wherein said treating step comprises contacting said material with about a 5-15% aqueous alkali solution for a time sufficient to dissociate said adduct.
 8. The method according to claim 5 wherein said treating step comprises contacting said material with gaseous ammonia for a time sufficient to dissociate said adduct. 